arm_pmu: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability

Since commit bd2756811766 ("perf: Rewrite core context handling") the
relationship between perf_event_context and PMUs has changed so that
the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally
silenced no longer exists.

Remove the capability and associated comment to avoid confusion that it
actually influences any perf core behavior. This change should be a
no-op.

Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20230724134500.970496-4-james.clark@arm.com

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 2e79201..d712a19 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -877,15 +877,12 @@ struct arm_pmu *armpmu_alloc(void)
                .attr_groups    = pmu->attr_groups,
                /*
                 * This is a CPU PMU potentially in a heterogeneous
-                * configuration (e.g. big.LITTLE). This is not an uncore PMU,
-                * and we have taken ctx sharing into account (e.g. with our
-                * pmu::filter callback and pmu::event_init group validation).
-                *
+                * configuration (e.g. big.LITTLE) so
                 * PERF_PMU_CAP_EXTENDED_HW_TYPE is required to open
                 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events on a
                 * specific PMU.
                 */
-               .capabilities   = PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDED_REGS |
+               .capabilities   = PERF_PMU_CAP_EXTENDED_REGS |
                                  PERF_PMU_CAP_EXTENDED_HW_TYPE,
        };